Flat Rock Lake Dam Reservoir Report

Last Updated: December 15, 2025

Flat Rock Lake Dam, located in Cedar Hill, Missouri, was completed in 1959 and serves as a vital water resource for the region.


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Summary

Owned privately, the dam stands at a height of 24 feet and has a storage capacity of 205 acre-feet. The primary purpose of the dam is for recreation, providing residents with a serene lake for boating, fishing, and other outdoor activities.

With a hazard potential rated as high, the condition of Flat Rock Lake Dam is currently not rated. Despite this, the dam remains a popular destination for water enthusiasts and climate advocates alike. Situated on TR to Big River, the dam offers a surface area of 16 acres and drains an expansive 2200-acre watershed, highlighting its crucial role in water management for the surrounding area.

Although not regulated by the state, Flat Rock Lake Dam presents an opportunity for further exploration and consideration in the realm of water resource management and climate resilience. As efforts continue to mitigate potential hazards and improve infrastructure, the dam stands as a symbol of the delicate balance between human interaction with natural resources and the importance of sustainable practices for future generations.

Year Completed

1959

Dam Height

24

River Or Stream

TR TO BIG RIVER

Primary Dam Type

Earth

Surface Area

16

Drainage Area

2200

Nid Storage

205

Structural Height

24

Hazard Potential

High

Foundations

Unlisted/Unknown

Nid Height

24
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.

Hazard Potential Classification

High
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.